Miniaturized switch device

• US 7,999,642 B2
• Filed: 03/03/2006
• Issued: 08/16/2011
• Est. Priority Date: 03/04/2005
• Status: Expired due to Fees

• Current Assignee: HT Microanalytical, Inc. (Rosenberger Technology (Kunshan) Co., Ltd.)
• Original Assignee: HT Microanalytical, Inc. (Rosenberger Technology (Kunshan) Co., Ltd.)
• Inventors: Christenson, Todd
• Primary Examiner(s): Mai; Anh T
• Assistant Examiner(s): Rojas; Bernard
• Application Number:
  US11/367,890
• Publication Number:
  US 20060197635A1
• Time in Patent Office: 1,992 Days
• Field of Search: 335/78, 200/181
• US Class Current: 335/78
• CPC Class Codes: H01H 2001/0078 with parallel movement of the movable contact relative to the substrate
• CPC Class Codes: H01H 2050/007 Relays of the polarised type, e.g. the MEMS relay beam having a preferential magnetisation direction
• CPC Class Codes: H01H 50/005 using micromechanics

Abstract

The present invention provides a switch suitable for efficient microfabrication. The switch elements are disposed in several layers. Various embodiments provide various switching capabilities and operational characteristics. The switches can be protected by suitable packaging, and can be efficiently fabricated in groups or arrays.

Claims

1. A microfabricated switch, comprising:

a) a base layer;

b) a moveable member layer substantially parallel to the base layer, having disposed therein a moveable member that is moveable between first and second positions, and where the moveable member is constrained to move substantially parallel to the base layer;

c) first and second terminals, mounted relative to the moveable member such that when the moveable member is in the first position electrical current can flow between the first and second terminals; and

d) an electromagnetic actuator comprising a coil, the electromagnetic actuator having north and south poles mounted such that the north and south poles are both disposed in the moveable member layer, and mounted relative to the moveable member such that the moveable member moves responsive to force applied from the electromagnetic actuator;

wherein the electromagnetic actuator and moveable member collectively define a closed-loop path for magnetic flux.

2. A switch as in claim 1, further comprising first and second contacts, where the first contact is in mechanical communication with the moveable member and in electrical communication with the first terminal, and wherein the second contact is in electrical communication with the second terminal, and wherein the first and second contacts mount relative to the moveable member such that the first and second contacts are in electrical communication when the moveable member is in the first position but not when the moveable member is in the second position.

3. A switch as in claim 2, wherein the first contact moves substantially parallel to the base layer responsive to motion of the moveable member.

4. A switch as in claim 3, wherein the first contact moves substantially within one of the base layer, the moveable member layer, or a third layer.

5. A switch as in claim 2, wherein the contacts are disposed substantially in the moveable member layer, and further comprising an insulating portion of the moveable member layer between the moveable member and each of the contacts.

6. A switch as in claim 1, further comprising an electromagnetic actuator, comprising magnet wire wound around a mandrel.

7. A switch as in claim 6, wherein the mandrel interfaces with north and south poles of the electromagnetic actuator via a castellated mechanical interface.

8. A switch as in claim 1, further comprising a housing that substantially prevents external contaminants from reaching the moveable member, and that allows electrical communication with the terminals.

9. A switch as in claim 8, wherein the moveable member layer mounts relative to the base layer on a first side of the base layer, and wherein the terminals are externally accessible on a second side of the base layer, and wherein the housing is substantially disposed on the first side of the base layer.

10. A switch as in claim 8, wherein the terminals are externally accessible in a first portion of the base layer, and wherein the housing mounts with a second portion of the base layer.

11. A switch as in claim 1, further comprising an electromagnetic actuator, comprising a mandrel around which is wound at least one of extruded wire or drawn wire.

12. A microfabricated switch, comprising:

a) A base layer;

b) A moveable member layer substantially parallel to the base layer, having disposed therein a moveable member that is moveable between first and second positions, and where the moveable member is constrained to move substantially parallel to the base layer;

c) First and second terminals, mounted relative to the moveable member such that when the moveable member is in the first position electrical current can flow between the first and second terminals;

d) First and second fixed members, each disposed in the moveable member layer such that each fixed member defines a gap between itself and a portion of the moveable member;

e) An electromagnet comprising a core surrounded by wires;

wherein the core is physically and magnetically coupled with each of the first fixed member and second fixed member, and wherein the core, first fixed member, and second fixed member collectively define a first pole and second pole, and wherein each of the first pole and second pole is located entirely within the moveable member layer, and further wherein the core, first fixed member, second fixed member, and moveable member collectively define a closed-loop path for magnetic flux.

13. The switch of claim 12, wherein the moveable member and first fixed member are separated by a first air gap when the electromagnet is not energized, and further wherein the moveable member and first fixed member are in physical contact when the electromagnet is energized.

14. The switch of claim 12, wherein the moveable member and first fixed member are in physical contact when the electromagnet is not energized, and further wherein the moveable member and first fixed member are separated by a first air gap when the electromagnet is energized.

15. A microfabricated switch comprising:

(1) a substrate;

(2) a moveable member layer comprising;

(a) a moveable member that is dimensioned and arranged to move along a direction substantially parallel with the substrate;

(b) a first terminal and second terminal, mounted relative to the moveable member such that (i) when the moveable member is in a first position a flow of a first electrical current between the first and second terminals is enabled and (ii) when the moveable member is in a second position the flow of the first electrical current between the first and second terminals is disabled; and

(c) a first fixed member and second fixed member, the first fixed member and second fixed member each comprising ferromagnetic material; and

(3) an electromagnet comprising (i) a core comprising ferromagnetic material and (ii) a winding that is dimensioned and arranged to enable the flow of a second electrical current through the winding;

wherein the core, first fixed member, and second fixed member are physically coupled such that the first fixed member comprises a first pole of the electromagnet and the second fixed member comprises a second pole of the electromagnet, and wherein each of the first pole and second pole is located entirely within the moveable member layer;

wherein the core, first fixed member, second fixed member, and moveable member collectively define a closed-loop path for magnetic flux; and

wherein the position the moveable member is based the flow of the second electrical current.

16. The switch of claim 15 wherein the moveable member layer defines a first plane, and wherein the core lies in a second plane that is entirely outside the first plane.

17. The switch of claim 15 wherein the moveable member layer defines a first plane, and wherein the core lies entirely within the first plane.

18. The switch of claim 15 wherein the moveable member is in the first position when the second electrical current flows through the second winding.

19. The switch of claim 15 wherein the moveable member is in the second position when the second electrical current flows through the second winding.